Although the delineations arent always clear-cut, the immune systems responses to pathogens can be roughly grouped into three categories: type 1, which is directed against viruses and certain bacteria that infiltrate our cells; type 2, which fights parasites like worms that dont invade cells; and type 3, which goes after fungi and bacteria that can survive outside of cells. Each branch uses different cytokines to rouse different subsets of molecular fighters.
The Coronavirus Outbreak
Frequently Asked Questions
Updated August 3, 2020
- Im a small-business owner. Can I get relief?
- The stimulus bills enacted in March offer help for the millions of American small businesses. Those eligible for aid are businesses and nonprofit organizations with fewer than 500 workers, including sole proprietorships, independent contractors and freelancers. Some larger companies in some industries are also eligible. The help being offered, which is being managed by the Small Business Administration, includes the Paycheck Protection Program and the Economic Injury Disaster Loan program. But lots of folks have not yet seen payouts. Even those who have received help are confused: The rules are draconian, and some are stuck sitting on money they dont know how to use. Many small-business owners are getting less than they expected or not hearing anything at all.
- What are my rights if I am worried about going back to work?
- Should I refinance my mortgage?
- It could be a good idea, because mortgage rates have never been lower. Refinancing requests have pushed mortgage applications to some of the highest levels since 2008, so be prepared to get in line. But defaults are also up, so if youre thinking about buying a home, be aware that some lenders have tightened their standards.
- What is school going to look like in September?
- It is unlikely that many schools will return to a normal schedule this fall, requiring the grind of online learning, makeshift child care and stunted workdays to continue. Californias two largest public school districts Los Angeles and San Diego said on July 13, that instruction will be remote-only in the fall, citing concerns that surging coronavirus infections in their areas pose too dire a risk for students and teachers. Together, the two districts enroll some 825,000 students. They are the largest in the country so far to abandon plans for even a partial physical return to classrooms when they reopen in August. For other districts, the solution wont be an all-or-nothing approach. Many systems, including the nations largest, New York City, are devising hybrid plans that involve spending some days in classrooms and other days online. Theres no national policy on this yet, so check with your municipal school system regularly to see what is happening in your community.
- Is the coronavirus airborne?
- The coronavirus can stay aloft for hours in tiny droplets in stagnant air, infecting people as they inhale, mounting scientific evidence suggests. This risk is highest in crowded indoor spaces with poor ventilation, and may help explain super-spreading events reported in meatpacking plants, churches and restaurants. Its unclear how often the virus is spread via these tiny droplets, or aerosols, compared with larger droplets that are expelled when a sick person coughs or sneezes, or transmitted through contact with contaminated surfaces, said Linsey Marr, an aerosol expert at Virginia Tech. Aerosols are released even when a person without symptoms exhales, talks or sings, according to Dr. Marr and more than 200 other experts, who have outlined the evidence in an open letter to the World Health Organization.
People with moderate cases of Covid-19 take what seems like the most sensible approach, concentrating on type 1 responses, Dr. Iwasakis team found. Patients struggling to recover, on the other hand, seem to be pouring an unusual number of resources into type 2 and type 3 responses, which is kind of wacky, Dr. Iwasaki said. As far as we know, there is no parasite involved.
Its almost as if the immune system is struggling to pick a lane, Dr. Wherry said.
This disorientation also seems to extend into the realm of B cells and T cells two types of immune fighters that usually need to stay in conversation to coordinate their attacks. Certain types of T cells, for instance, are crucial for coaxing B cells into manufacturing disease-fighting antibodies.
Last month, Dr. Wherry and his colleagues published a paper in Science finding that, in many patients with severe Covid-19, the virus had somehow driven a wedge between these two close-knit cellular communities. Its too soon to tell for sure, but perhaps something about the coronavirus is preventing B and T cells from talking to each other, he said.
These studies suggest that treating bad cases of Covid-19 might require an immunological reset drugs that could, in theory, restore the balance in the body and resurrect lines of communication between bamboozled cells. Such therapies could even be focused on specific subsets of patients whose bodies are responding bizarrely to the virus, Dr. Blish said: the ones who have deranged cytokines from the beginning.
But thats easier said than done. The challenge here is trying to blunt the response, without completely suppressing it, and getting the right types of responses, Dr. August said. Its hard to fine-tune that.
Timing is also crucial. Dose a patient too early with a drug that tempers immune signaling, and they may not respond strongly enough; give it too late, and the worst of the damage may have already been done. The same goes for treatments intended to shore up the initial immune response against the coronavirus, like interferon-based therapies, Dr. Blish said. These could stamp out the pathogen if given shortly after infection or run roughshod over the body if administered after too long of a delay.